Method of making polyoxyalkylene ethers



Patented Mar. 11, 1952 I METHOD OF MAKING POLYOXYALKYLENE ETHERS B. Robert Schwartz, Union, N. J assignor to Hart Products Corporation, a corporation of New York No Drawing. Application June 21, 1949, Serial No. 100,541

7 Claims. (01. 260-609) The invention relates to a method of making polyoxyalkylene ethers.

The polyoxyalkylene ethers are in extensive use as surface active agents. The most common of these is made by the introduction of ethylene oxide into a reactive molecule.

In this conventional method of manufacture,

it is necessary to have a supply of ethylene oxide. This oxide is a gas at ordinary temperatures; pressure equipment is necessary in combining it with the selected base material. Also the ethylene oxide, if accidentally mixed with air, is explosive if ignited. As a. result, the use of ethylene oxide is accompanied by such hazard or the need of such special equipment as to preclude the small manufacturer from making the polyoxyethylene ether. I

I have now discovered a method that is simple; and convenient, avoids alike the use of pressure equipment and a gas-that is explosive when mixed with air, and gives a good yield of the desired product.

Briefly stated, my invention comprises the method of coupling together component parts of the desired polyoxyalkylene ether by means of a polyhalogenated linking agent. i More specifically the method includes forming a mixture of a nonvolatile alkali, a linking agent such as a polyhalogenated di-lower-alkyl ether, a polyglycol, and an acidic compound selected from the group consisting of mercaptans, phenols and cresols, heating the resulting mixture until there is formed a salt of the electropositive part of the alkali with the halogen of the linking agent used, and then separating the salt from the remaining polyoxyalkylene ether.

The reaction preparation is illustrated by the following equation in which an alkyl mercaptan is used as the acidic monohydric alcohol, B,B' dichlorodiethyl ether as the linking agent, a polyglycol, and

In this reaction R represents an alkyl group and a: any integral number between 1 and 100. The number of oxyethylene groups in the finished ether is increased by two from the linking agent, to a;+2, the increase being due to the ethylene groups in the chlorether used. The number of oxyethylene groups in the finished product is critical only when the finished product is to be a surface active agent. In that case, a: in the involved in this method of 2 formula should be 6 to 25. Fewer than 6 units of the oxyethylene makes the product not sufficiently hydrophylic; more than 25 units gives a product not sufiiciently hydrophobic. The surface active agent requires both properties.

A phenol or cresol may be substituted for the mercaptan (RS.H).. If cresol CH3C6H4OH is substituted for the mercaptan, then the finished ether will contain the group CHaCsHaO in place of RS in the formula for the polyoxyalkylene ether produced according to the equation above. Likewise if the CH3 group of the cresol is replaced by hydrogen or by an alkyl group R, then the H or the R would appear in the finished ether in place of CH3v of the group CHBC6H40.

The coupling of molecules by formation of salt as a by-product is a known type of chemical reaction. In such a reaction, it is understood, that, Where a coupling may proceed in each of several different manners, the coupling does pro?- ceed in those different possible ways. In the re?- action illustrated by the equation above, there are at least three courses for the reaction or alternative linkages that. are possible. In fact, it may be estimated on the basis of chemical statistics that the yield of the polyoxyalkylene ether should be only 30% or so of the total linked products.

When, however, I use the materials of the class illustrated, in the equation and stated herein as alternatives for those materials, then I obtain not this low yield but a yield approaching or exceeding of the theoretical yield of the one com.- pound, the desired polyoxyalkylene ether.

. The polyoxyalkylene. ethers made as described herein will vary with the particular homologs selected from within the permissible classes of reacting ingredients. When the polyglycol selected is a. polyethylene glycol. the linking agent is one of the polyhalogenated lower dialkyl ethers, and the number of carbon atoms in the acidic compound such as .themercaptan and the phenol or cresol contains 6 to 18 carbon atoms to the mole,- cule, then the polyoxyalkylene ether made will range from an oil to a wax-like product that varies from clear solubility in water to insolubility in water and solubility in paraflin oil. The higher the proportion of carbon and hydrogen in the finished ether the less becomes the solubility in water and the higher the solubility in paraflin oil. All of the products, are surface active agents and this property will vary in degree with the length of the polyglycol ether chain and the balancing of the hydrophobic-and hydrophilic groups within the molecule of the finished ether.

The acidic. compound furnishes the active or replaceable hydrogen. Examples of the acidic compound that may be used are the mercaptans of the formula RSH in which R is an alkyl containing 6 to v24 carbon atoms. Other examples are the aromatic alcohols such as the phenols and cresols containing each only 1 hydroxyl group to the molecule.

The linking agent is polyfunctional in alkaline media. For this there may be used a polyhalogenated ether containing 2 or more halogen atoms to a molecule. The chlorinated product is preferred, as there is no advantage in using the bromo, iodo, of fluoro ethers that offset the disadvantages in the use of these alternatives including particularly the disadvantage of extra cost of the ethers containing halogen other than chlorine. I obtain the best results and better control of the reaction when only 2 halogen atoms are present in the molecule of the linking agent. Examples of the halogenated ethers that may be used are the BB dichloro diethyl ether or the corresponding diisopropyl, diisobutyl or dimethyl ethers or their trior tetrachlorinated derivatives. Polyhalogenated lower paraflins may be used as linking agents, as, for instance, dichlorinated methane, ethane, propane, butane, or hexane, or the corresponding trichlor or tetrachlor derivatives.

As the polyglycol I may use polyethylene glycol, polypropylene glycol, or polybutylene glycol. The polyethylene glycol is represented by the general vformula HO.(C2H4O) :aOI-I in which :1: stands for an integral number within the range 1 to 100. The number of alkylene oxide units contained in the molecule of polyglycol is not critical.

The alkali used is one that it not volatile under the conditions of treatment to be described. The preferred alkali is sodium hydroxide, although there may be used potassium hydroxide. lithium hydroxide, or other alkali metal hydroxide. In the course of the reaction the elctropositive ingredient, represented by the alkali metal in these examples, combines with the halogen of the linking agent, to form a halide salt.

As to proportions, there must be sufficient of the alkali to remove halogen atoms from the halogenated linking agent in proportion to develop linkages with two monovalent groups. This means that there must be used 2 mole of the alkali such as sodium hydroxide for each mol of the polyhalogenated agent. Actually I prefer to use an excess of the alkali since it is the cheapest of all. of the reagents; the excess promotes proper utilization of the other and more expensive ingredients. Thus I may use excesses up to 100% or more of the theoretical quantity of alkali.

The other reagents constituting the three classes of organic reactants are used to advantage in equivalent proportions. When the halogenated ether used contains 2 halogen atoms, then all organic materials are used in equimolecular proportions. If an excess of any one reactant is used, the portion in excess remains unused in the finished product.

In general the methodof manufacture include heating the mixture of the kind described at a selected temperature not above the boiling point,

of the mixture and below the temperature of substantial pyrolytic decomposition of any ingredient of the mixture. Ordinarily I use temperatures within the range 100 C. to 250 Q.

Heating at the selected temperature is continued until the desired reaction is substantially complete and the halogen has been removed from the linking agent and converted to a salt with the electropositive part of the alkali, that is, to sodium halide when the alkali used is sodium hydroxide. Then the heating is discontinued and the said salt is separated from the remaining polyoxyalkylene ether. This separation is effected to advantage by adding sufficient water to form a solution of the salt that when hot is nearly saturated, heating the resulting mix to approximately the temperature of boiling, allowing the heated materials to separate in two layers, and then drawing off the lower or salt layer from the overlying layer of polyoxyalkylene ether.

The invention will be illustrated in greater detail by description in connection with the following examples. Proportions here and elsewhere herein are expressed as parts by weight unless otherwise specifically stated.

Ezcample 1 26.2 parts by weight of dodecyl phenol (obtained by condensing phenol with triisobutylene) 15.8 parts by weight of BB dichlorodiethyl ether, 42 part by weight of polyethylene glycol No. 400 (an ethylene oxide polymer of 8 ethylene oxide units having an average molecular weight of about 400), and 10 parts of sodium hydroxide are mixed together with good agitation and slowly heated to a temperature of 170 C. After the evolution of water has taken place, the reaction mixture is kept at this temperature for l. to 5 hours, in order to obtain a good yield of the desired product. The reaction can be followed by the salt content which increases during the reaction until it becomes constant at the end of the reaction. The reaction product is an alkyl phenyl ether of polyglycol containing 10 units of glycol (8 units from the polyethylene glycol and 2 units from the 13,13 dichlorodiethyl ether). The product is then mixed with an equal volume of saturated salt solution, neutralized to a pH of '7, and allowed to stand 1 hour at C., after which the lower salt layer is drawn ofi and dis-' carded. The upper layer is the alkyl phenyl ether (clear oil) which shows good washing results on wools particularly in the presence of alkalies.

Example 2 not. The reaction can be followed by the salt content which increases during the reaction until it becomes constant at the end of the reaction. The reaction product is the cctyl phenyl ether of polyglycol containing 10 units of glycol. The product is purified as in Example 1. The upper layer is the alkyl phenyl ether (clear oil)- which shows excellent surface active properties.

By reacting other polyglycols ranging from 4' to units of ethylene oxide with isooctyl phenol in this manner, reaction products are obtainedwith a great variation in molecular weight which can be used for various purposes to take advan tage of the increased or decreased solubility and chain length Example 3 220 parts of isononyl phenol, 18.9 parts of 3,13. dichlorodi-isopropyl ether, 63.0 parts of polyglycol No. 600 (containing 12 units of ethylene oxide), and 100 parts of sodium hydroxide are mixed together, processed and purified as in Example 1. The upper layer is the isononyl phenoxy diisopropyl ether of polyglycol No. 600 which shows good Wetting and scouring action.

Example 4 29.0 parts of tetradecyl phenol (obtained by condensing tetradecene with phenol), 15.8 parts of BB dichlorodiethyl ether, 63.0 parts of polyglycol No. 600, and 10.0 parts of sodium hydroxide are mixed together, processed and purified as in Example 1. The reaction product is the tetradeeyl phenyl ether of polyglycol consisting of 14 molecular proportions of glycol.

Example 5 Example 6 Example 6 is repeated using 42 parts of polyethylene glycol No. 200 instead of No. 300. The purified product is the dodecyl sulfide of polyglycol consisting of molecular proportions of glycol. One half a part of this product per liter of water wets out a 5 gram skein according to the Draves wetting test in 20 seconds.

Example 7 Example 5 is repeated using 63 parts of poly-- ethylene glycol No. 600 instead of No. 300. The purified oil is the dodecyl sulfide of polyglycol consisting of 14 molecular proportions of glycol. The product showed excellent scouring and sudsing action and clear solubility in water.

Example 8 Example No. 5 is repeated using 16 parts of polyethylene glycol No. 300 and 21 parts of polyethylene glycol No. 400 instead of polyethylene glycol N0. 300 alone. The purified oil is a mixture of dodecyl sulfide of polyglycol consisting of 10 molecular and 8 molecular proportions of glycol 0.05% of the product wets out a 5 gram skein according to the Draves wetting test in 25 seconds.

Example 9 Example No. 5 is repeated using 105 parts of polyethylene glycol No. 1000 instead of No. 300.

The purified material is the dodecyl sulfide of polyglycol consisting of 22 molecular proportions of glycol.

Example 10 23.0 parts of tetradecyl mercaptan, 15.8 parts of 3,13 dichlorodiethyl ether, 31.5 parts of polyethylene glycol No. 300 and 10.0 parts of sodium hydroxide are mixed together, processed and purified as in Example 1. The reaction product is the tetradecyl sulfide of polyglycol consisting of a molecular proportions of lycol which shows excellent scouring action on wool.

Example 11 Example No. 10 is repeated using 63 parts of polyethylene glycol No. 600 instead of No. 300.

The purified oil is largely the tetradecyl sulfide of polyglycol consisting of 14 molecular proportions of glycol. The product showed excellent cotton and wool scouring action and clear solubility in water.

Example 12 25.8 parts'of hexadecyl mercaptan, 15.8 of B, B dichlorodiethyl ether, 42 parts of polyethylene glycol No. 400, and 10.0 parts of sodium hydroxide are mixed together, processed and purified as in Example 1. The reaction product is the hexadecyl sulfide of polyglycol consisting of 10 molecular proportions of glycol which shows exceptional scouring action on woolen fabrics.

Example 13 Example No. 12 is repeated using 63 parts of polyethylene glycol No. 600 instead of No. 400. The purified oil is largelythe hexadecyl sulfide of polyglycol consisting of 14 molecular proportions of glycol. The product is clear soluble in water and shows exceptional scouring action on cottons and woolens.

Example 14 Example No. 1 is repeated usin 21 parts of polyethylene glycol No. 200 instead of No. 100. The purified oil is largely the dodecyl phenyl ether of polyglycol containing 6 units of glycol which shows limited solubility in water. The product is dried and then sulfated with an equal weight of 99% sulfuric acid at 20 C., neutralized to a slight alkalinity with 25% caustic soda at temperatures under 30 C. The product, a dodecyl phenyl ether glycol sulfate, was a cream White paste possessing excellent sudsing and washing action.

It will be understood also that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of illustration which do not constitute departures from the spirit and scope of the invention.

What I claim is:

method which comprises forming a mixture containing approximately 2 mols at least of a nonvolatile alkali, 1 mol at least of a polyhalogenated linking agent, 1 mol of a polyglycol, and 1 mol of an acidic compound selected from the group consisting of mercaptans, phenols and cresols, heating the mixture to a temperature within the range 100 to 250 0., continuing the heating until there is formed a halide salt of the electropositive component of the said alkali and a polyoxyalkylene ether and until there is no substantial additional formation of the said salt, and then separating the salt from the polyoxyalkylene ether, the polyoxyalkylene ether including a residue representing the linking agent less at least2 halogen atoms and this residue linking the group representing the polyglycol less 1 hydrogen of an original hydroxyl radical and a second group representing the said acidic compound less l'replaceable hydrogen.

2. The method described in claim 1, the polyhalogenated linking agent used being a polyhalogenated ether, the alkali used being an alkali metal hydroxide, and the said salt formed bein glycol used being of the general formula HO. (Cal-I40) I-OH in which in represents an integral numberwithin the range 1 to 100, the linking agent being B,B dichlordiethyl ether and the polyglycol and the said acidic compound being used in approximately equimolecular proportions, the alkali being alkali metal hydroxide in the proportion of at least 2 mols for each mol of the dichlorether, and the temperature of heating being 100 to 250 C.

5. The method described in claim 1, the said acidic compound being a mercaptan.

6. The method described in claim 1, the said acidic compound being a phenol.

7. The method described in claim 1, the polyhalogenated linking agent being a polyhalogenated aliphatic hydrocarbon.

B. ROBERT SCHWARTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,970,578 Schoeller et al. Aug. 21, 1934 2,111,234 Zellhoefer Mar. 15, 1938 2,146,324 Zellhoefer et a1 Feb. 7, 1939 2,425,755 Roberts et al Aug. 19, 1947 2,425,845 Toussaint et al Aug. 19, 1947 2,520,612 Roberts et al Aug. 29, 1950 

1. IN MAKING A POLYOXYALKYLENE ETHER, THE METHOD WHICH COMPRISES FORMING A MIXTURE CONTAINING APPROXIMATELY 2 MOLS AT LEAST OF A NONVOLATILE ALKALI, 1 MOL AT LEAST OF A POLYHALOGENATED LINKING AGENT, 1 MOL OF A POLYGLYCOL, AND 1 MOL OF AN ACIDIC COMPOUND SELECTED FROM THE GROUP CONSISTING OF MERCAPTANS, PHENOLS AND CRESOLS, HEATING THE MIXTURE TO A TEMPERATURE WITHIN THE RANGE 100* TO 250* C., CONTINUING THE HEATING UNTIL THERE IS FORMED A HALIDE SALT OF THE ELECTROPOSITIVE COMPONENT OF THE SAID ALKALI AND A POLYOXYALKYLENE ETHER AND UNTIL THERE IS NO SUBSTANTIAL ADDITIONAL FORMATION OF THE SAID SALT, AND THEN SEPARATING THE SALT FROM THE POLYOXYALKYLENE ETHER, THE POLYOXYALKYLENE ETHER INCLUDING A RESIDUE REPRESENTING THE LINKING AGENT LESS AT LEAST 2 HALOGEN ATOMS AND THIS RESIDUE LINKING THE GROUP REPRESENTING THE POLYGLYCOL LESS 1 HYDROGEN OF AN ORIGINAL HYDROXYL RADICAL AND A SECOND GROUP REPRESENTING THE SAID ACIDIC COMPOUND LESS 1 REPLACEABLE HYDROGEN. 